1. FIELD
The subject invention is in the field of methods and apparatus for removing paraffin and asphaltene from the rod string and tubing of oil wells while the rod string is being removed from the well and after removal of the tubing.
2. PRIOR ART
The U.S. patents listed below are a sampling of the patented prior art in this field.
______________________________________ 3,475,781 4,895,205 4,279,300 5,101,896 4,399,869 5,168,929 ______________________________________
In prior art apparatus in this field, such as the apparatus of Thompson, U.S. Pat. No. 4,895,205, there is a housing attachable to the head of an oil well. The housing is fitted with nozzles and scrapers. When a string of rods is moved through the housing liquids are sprayed through the nozzles so that, in combination with the action of the scrapers, contamination is removed from the rods. The removed contamination, including paraffin and asphaftene, is deposited either in the well or outside of the housing, thus contaminating the well and/or the environment and equipment around the well head. Contamination of the well may interfere with or prevent reinstallation of equipment in the well, requiring expenditure of money and time to remove the contamination. Decontaminating the equipment and environment around the well head also requires expenditure of time and money and can be hazardous to health of personnel doing the work, particularly when noxious gases art present.
Accordingly, the primary objective of the subject invention is to provide apparatus for cleaning oil well components such as the rod string and tubing without contamination of the well or the environment around it. Other objectives are that the apparatus be dependable and easily transportable.